Subject: Tagging:summary of note on bottlenose dolphin rxns to tagging (fwd)

Mike Williamson (pita@www1.wheelock.edu)
Tue, 14 Apr 1998 11:02:16 -0400 (EDT)

---------- Forwarded message ----------
Date: Fri, 10 Apr 1998 13:39:18 -0400
From: "Robin W. Baird" <rwbaird@is.dal.ca>
To: MARMAM@UVVM.UVIC.CA
Subject: summary of note on bottlenose dolphin rxns to tagging

Schneider, K., R.W. Baird, S. Dawson, I. Visser and S. Childerhouse.
1998. Reactions of bottlenose dolphins to tagging attempts using a
remotely-deployed suction-cup tag. Marine Mammal Science 14:316-324.

There was no abstract for this Note, but a summary is presented below.
Reprints can be requested from rwbaird@is.dal.ca


Summary

In order to study the diving behaviour of bottlenose dolphins in
Doubtful Sound, New Zealand, the authors attempted to tag bowriding
dolphins with a suction-cup attached time-depth recorder/VHF radio
tag. The note describes the immediate reactions of both tagged
individuals and other dolphins within the same group, as well as the
behaviour of the dolphins when they were encountered on subsequent
days. A total of 17 tagging attempts were made between 24 and 29
October 1995. The tag contacted a dolphin in 10 cases, and remained
attached for > 10 seconds in five of these. In each of the five cases
in which the tag contacted and stuck, the tagged animal immediately
began a bout of high-energy behaviours, apparently to dislodge the
tag. Tags remained attached on these dolphins for periods of about 10
seconds to about three minutes. Group speed and the number of leaps in
the group increased in 5/5 and 4/5 of these cases, respectively. In
general, reaction intensity decreased in the order: successful
attachments > unsuccessful attachments > misses. Within several days
of initiating tagging attempts, the frequency of bowriding behaviour
in the population decreased, and slowly returned to "normal" over the
next two months. Based on both the reactions exhibited by individual
dolphins and those in the surrounding group, and on the inability of
the suction-cup tag to remain attached during leaps and high speed
swimming, the authors suggest that suction-cup tagging of this
population of bottlenose dolphins is not feasible. Reactions of
bottlenose dolphins were substantially greater than have been observed
for similar studies using these tags on killer whales and Dall's
porpoise.






==========================================================
Robin W. Baird, Ph.D.
Biology Department, Dalhousie University, 1355 Oxford St.,
Halifax, Nova Scotia B3H 4J1 Canada
Phone (902) 494-3723
Fax (902) 494-3736
e-mail: rwbaird@is.dal.ca
http://is.dal.ca/~whitelab/index.htm